Return bend



Dec. 17, 1935. J. E. GETZEN 2,024,572

' RETURN BEND Filed April 18, 1933 2 Sheets-Sheet 1 FIG. I.

Fla-5.

Dec. 17, 1935.

J. E. GETZEN 2,024,572

RETURN BEND Filed April 18, 1953' 2 Sheets-Sheet 2 NEY Patented Dec. 17,1935 UNITED STATES PATENT QFFICE RETURN BEND- John E. Getzen,Birmingham, Ala., assignor to Fred C. Fantz, Webster Groves, Mo.

' Application'April 18, 1933, Serial No. 666,651

Claims. (Cl. 285-29) My invention relates to that class of return bendswhich are employed in the cracking coils or tube nests of crackingplants in refineries. It is well known that in the operation of crackingthat coke deposits on the inside of the. tubes and that this coke, ifpermitted to accumulate, is

highly dangerous as it tends to cause fires which result in damage toproperty, loss of time caused by the shut down of the still due to thefire, and sometimes to very great loss of life.

Because of this condition it is necessary to remove the accumulated cokefrom the interior of the still tubes. This is accomplished by openingthe ends of the tubes and inserting a rotary tube cleaner which cuts outthe coke from the inside of the tube until the tube is bright. Instandard practice this is accomplished by means of what is called an Hshaped header box or return bend which is provided with threaded plugswhich are 29, screwed into the header box. These plugs must be unscrewedto permit the insertion of the-rotary tube cleaner. Great difficulty isexperienced with these plugs 1 as they frequently cannot be removed evenwhen as many as five or six men 5 are placed on theend of a 5 footwrench and they haveto be burned out with an acetylene torch.

.If one plug sticks, it means that the still must stay shut down untilrepairs are made.

It is well known in the industry that the down time is far moreexpensive than the cost of repairs or replacements. Therefore everythingthat can possibly be done, is done to shorten the down time of a still.As a consequence it has lately 5 become the practice to employ aremovable return bend which is fitted to the ends of the tubes fit andwhich is mounted in a housing provided with toggles to hold the returnbend tightly against the ends of the tubes forming a leak-proof joint.By 49 removing these togglesthe U bend can be removed and the rotarytube cleaners inserted in the tube.

It also frequently happens in the operation of a refinery that itbecomes necessary to remove a tube from the still coil or bank and withthe 4.5 standard practice it was generally necessary to destroy aperfectly good tube by cutting it ofi in order to remove the defectiveone. As a consequence there has been a growing practice lately to employa demountable tube in which the tube 50 is upset with a shoulder andsectional metal rings are mounted intermediate the shoulder and annularportions of the housing which encircle the tubes. In this way the tubecan be demountably 55 tion or replacement at will.

My present invention has for its object to provide a construction whichwill avoid the necessity of using the sectional metal bushing and at thesame time will provide an improved manner of holding the housingsections together. The 5 means usually employed for this purpose requiresome sort of extraneous devices such as bolts, etc., to hold them inposition. My improved invention provides for a, construction which willof itself hold the securing means in place when the return bend assemblyis ready for operation.

My means of accomplishing the foregoing objects may be more readilyunderstood by having reference to the accompanying drawings which arehereunto annexed and are a part of this specification, in which- Fig. lis a side elevation of a. return bend constructed in accordance with myimprovement, one-half of it being shown in section, so as to show theinterior construction;

Fig. 2 is a bottom view of the same;

Fig. 3 is an end elevation of the return bend fitting, all of the partsbeing assembled in position;

Fig. 4 is an end elevation of the housing section showing the manner ofremoving them from the means for holding them together; and

Fig. 5 is a bottom view of the housing section as shown in Fig. 4.

Similar reference numerals refer to similar parts throughout the entiredescription. As shown in the drawings, a conventional U or return bendl, is mounted upon the ends of still tubes 2 and 3 so as to provide acontinuous passageway therethrough. The ends of the tubes 2 and Bareupset forming shoulders i. As the construction for mounting the tubes isidentical I shall only describe one of them.

The housingis formed, as illustrated, in two sections, each of which isprovided with two semicircular portions adapted to encircle one-half of40 the tubes 2 and 3. The semi-circular portions 5 and 6 are providedwith extensions 1 and 8, the inner surface of which forms shoulders 9which are adapted to engage the shoulders 4 and formed by the upsettingof the tubes 2 and 3. The housing is provided with upwardly extendingside walls It] and H. Slots it are formed in the upwardly extending sidewall and in these slots are mounted toggles l3 which'carry set screwsis, the inner ends of which engage abutments i5 formed on the 5 externalwall of the return bend l.

The sides l6 and H of the extensions 1 and 8 are milled ofi, as veryclearly seen in Fig. 2. The meeting or adjacent faces l8 and [9 of theextensions l and 8 cut away asclearly seen in Fig. 3.

These extensions 1 and 8 are each provided with a peripheral bead and2|. Around the extensions and 8 I mount an annular member 22, thepurpose of which is to hold the sections firmly together when inassembled position.

The device is assembled in the following manner: The annular member 22is passed over the ends of the tubes 2 and 3 and the sections of thehousing are then placed so that the arcuate shoulders 9 are below theshoulders 4 formed on the ends of the tube. The housing is then swunginto the position shown in full lines in Fig. 4, the cutaway portions l8and [9 of the faces of the extensions 1 and 8 permitting this movement.When in this position, the annular member can be moved up and over theextensions 1 and 8. The housing sections are then swung into theposition shown in full lines in Fig. 3 and the annular member 22 servesto hold them tightly together. It will be apparent from the foregoingdescription that it would be impossible to pass the extensions with thebead 2i! and 2| formed on their periphery through the ring if theextensions 1 and 8 were complete semi-circles at their periphery. Itherefore provide for milling off the sides as shown in Fig. 2 untilthey are cut away sufi'iciently so as to clear the inside of the ring orannular member 22. This is very clearly seen in Fig. 5, an inspection ofwhich shows that when the housing sections are in the position shown infull lines in Fig. 4 they have ample clearance to pass through theinterior of the annular member 22.

It will be apparent from the foregoing that by this construction Iprovide very secure and rigid means for holding the housing sectionstogether. Yet when the housing sections are removed the retaining ring22 will only drop on the tube until it strikes the tube sheet where itwill be in position for use when the housing is to be replaced.

Although I have described separate rings it will be obvious to personsskilled in the art that these rings may, if necessary, or desired, beconnected without departing from the scope of my invention.

Having described my invention what I regard as new and desire to secureby Letters Patent is:

1. In a refinery apparatus, a conventional return bend adapted toconnect a pair of shouldered tubes to provide a continuous passagewaytherethrough, a housing for said return bend comprising mating sectionseach having inwardly extending arcuate shoulders adapted to engage saidtubes to meet the shoulders thereon, extensions on said sections whichpartially surround said tubes, annular members which surround saidextensions and hold said sections in position, means on said extensionsto hold said annular members in place, the adjacent faces of saidextensions being cut away, and means mounted in said sections to forcethe return bend and tubes into a leakproof joint.

2. In a refinery apparatus, a conventional return bend adapted toconnect a pair of shouldered tubes to provide a continuous passagewaytherethrough, a housing for said return bend comprising mating sectionseach having inwardly extending arcuate shoulders adapted to engage saidtubes to meet the shoulders thereon, extensions on said sections whichpartially surround said tubes, annular members which surround saidextensions and hold said sections in position, a peripheral bead formedon each of said extensions which said annular member abuts, the adjacentfaces of said extensions being cut away, and means mounted in saidsections to force the return bend and tubes into a leak-proof joint.

3. In a refinery apparatus, a conventional return bend adapted toconnect a pair of shouldered tubes to provide a continuous passagewaytherethrough, a housing for said return bend comprising mating sectionseach having inwardly extending arcuate shoulders adapted to engage saidtubes to meet the shoulders thereon, extensions on said sections whichpartially surround said tubes, annular members which surround saidextensions and hold said sections in position, means on said extensionsto hold said annular members in place, means mounted in said sections toforce the return bend and tubes into a leak-proof joint, the sides ofsaid extensions at right angles to their meeting edges being milledaway.

4. In a refinery apparatus, a conventional return bend adapted toconnect a pair of shouldered tubes to provide a continuous passagewaytherethrough, a housing for said return bend comprising mating sectionseach having inwardly extending arcuate shoulders adapted to engage saidtubes to meet the shoulders thereon, extensions on said sections whichpartially surround said tubes, annular members which surround saidextensions and hold said sections in position, a peripheral bead formedon each of said extensions which said annular member abuts, the adjacentfaces of said extensions being cut away, means mounted in said sectionsto force the return bend and tubes into a leak-proof joint, the sides ofsaid extensions at right angles to their meeting edges being milledaway.

5. In a refinery apparatus, a conventional return bend adapted toconnect a pair of shouldered tubes to provide a continuous passagewaytherethrough, a two part housing for said return bend each part havingtwo upwardly extending side walls, a web formed integral with said wallswhich connects them, said housing comprising mating sections, eachhaving inwardly extending arcuate shoulders adapted to engage each ofsaid tubes to meet the shoulders thereon, extensions on said sectionswhich partially surround said tubes, annular members mounted on saidsections to hold said shoulders in engagement with said tubes, meansformed on said extensions to hold said annular members in place,detachable means mounted in said upwardly extending side walls to forcethe return bend and tubes into a leak proof joint, the abutting faces ofsaid extensions being cut away to permit the mounting of said annular'means thereon.

JOHN E. GETZEN.

